group 2 Flashcards
(14 cards)
group 2 elements electron configuration - what ion formed during redox reactions
s2 , 2+ ion
relative reactivity down group 2
more reactive - ionisation energy decrease due to atomic radius, shielding
redox reaction of mg -> ba with oxygen
- BURN in oxygen to form oxides
redox reaction of mg -> ba with water
- react with water to form hydroxides
Be doesn’t react - Ba rapidly reacts
redox reaction of mg -> ba with dilute acid
- react with dilute acid to form a salt and hydrogen
- more vigiourously react as u go down
formula for first and second ionisation energy of group 2 metals
1st ionisation energy: m -> m+ + e-
2nd ionisation energy: M+ -> M2+ + e-
overall: M -> M2+ + E-
trend in 1 and 2 ionisation energy affect on reactivity
2nd ionisation energy is higher than 1st meaning it requires more energy to remove the 2nd electron making the 2nd ionisation removal more reactive as u go down
action of water on oxides and hydroxides made from group 2 metals
- oxides and hydroxides are bases, most soluble (EXCEPT MG - REACTS SLOWLY AND HYDROXIDE ISNT THAT SOLUBLE) in water so also alkalis.
- Oxides react with water QUICKLY to form metal hydroxides that dissolve,
- The hydroxides OH- ions make solution strongly alkaline. PH (8-14)
trend in alkali solutions as u go down group
more strongly alkaline
Use of group 2 compounds (alkaline earth metals) w ionic equation
neutralise acidity
ionic equation: H+ + OH- -> h20
use of Ca(OH)2
calcium hydroxide is used in agriculture to neutralise acidic soils
use of Mg(OH)2 and CaC03
magnesium hydroxide and calcium carbonate are used in indigestion tablets as antacids
systematic name for kcl04
potassium chlorate (VII
use oxidation state of the central atom (CL = +7) for the Roman numerals value.
barium nitrate, sodium sulphate
Ba(no3)2, Na(so3)
